Dear All
May some of you will explain the question for me? Thanks!
I¡¯m going to do some RF MEMS research and have some puzzle.
Some have done microwave transline on surface of high resistivity silicon
substrate. So my question is?
First. Are all high-resistivity  silicon wafer the same? Are there some kind of
high-resistivity silicon wafer which has higher microwave loss but still has
high-resistivity? For example, it is possible that a silicon wafer has high
impurity level while it¡¯s resistivity is still high, because the
impurity are not ionized, providing no carriers.

The second, what the silicon dioxide layer (buffer layer) is for? Is silicon
dioxide layer of 1 micron thick enough? Because it is some difficult for me to
thermal growth dioxide layer of 2 micron thick.

Best Regards!